The fuel-delivery system in a vehicle, such as an automobile, includes a fuel tank, a fuel pump, a filter and an injection unit which has a set of injectors that spray the fuel into the manifold/cylinders. There are two basic types of injection units currently in use. A single-point or throttle-body injection unit has one or two injectors which spray the fuel into the manifold. A multi-port injection unit has at least one injector per cylinder. A line couples the fuel pump to the injection unit. There is also a return line from the injection unit back to the tank. There are couplers in the lines at selected points, as well as couplers between the lines and the pump, the tank and the injection unit.
In order to test the components of the fuel-delivery system, namely, the pump, the injectors, the regulator associated with the injection unit, the filter, the lines and/or the couplers, mechanics commonly use a pressure-testing apparatus that can be inserted into the system. Such apparatuses inform the mechanic of the pressure at selected points in the system. The amount of the pressure, as well as variations thereof, will inform the mechanic of defects in the fuel-delivery system. For example, the pressure may indicate that the fuel pump is defective or an injector or the regulator are leaking or there is a leak in a line or in a coupler.
Apparatuses of this type currently in the marketplace comprise adapters which are applied to a selected point in the fuel system. The adapters are installed with a wrench. Such an apparatus includes additional components which must be assembled and then attached to the adapters also using tools. When the mechanic has determined the pressure, he must reverse the steps, detaching the apparatus from the adapters and the adapters from the fuel system. Sometimes it is necessary to install the testing apparatus at a different point in the fuel system or simply reverse the apparatus. Either action requires detaching the adapters, detaching the rest of the mechanism from the adapters, both with the use of tools, coupling different adapters at the selected point in the fuel system and then reattaching the rest of the testing apparatus.
The couplers of other vehicles are likely to have different constructions and, in order to apply the pressure-testing apparatus, each of them require different adapters and different components to connect to the adapters. Each time an adapter is applied, tools are necessary and each time the balance of the testing apparatus is attached, tools are again required.
These testing apparatuses are also useable to deliver solvents to the injection unit for use in cleaning the injectors. But, the need for tools, again, to attach the adapters and the rest of the apparatus is undesirable.
Certain fuel-injection units include a testing port to which the testing apparatus may be applied. Current pressure-testing apparatuses can be used with the port, but they suffer similar disadvantages as those described above. An adapter is applied to the port using tools and then the balance of the testing apparatus is attached to the adapter.